Patent GB-1111375-A (GB)
Title: Improvements relating to devices for adjusting the transverse wire spacing in wire mesh welding machines
IPC: B21F27/10
Filed: 1966-10-11
Abstract: 1,111,375. Welding by pressure. EVG ENTWICKLUNGS-U. VERWERTUNGS G.m.b.H. 11 Oct., 1966 [31 Jan., 1966], No. 45437/66. Heading B3R. An adjustment device for fitting to a wire mesh welding machine to adjust the stroke of the mesh advancing mechansm and thus the spacing between the welded transverse wires comprises an adjustment shaft on which are mounted two or more angularly adjustable cams each co-operating with a separate cam follower coupled to a servo system which rotates the shaft through an angle to a predetermined angular orientation dependent on the shape and angular setting of the cams, the couplings between the cam followers and the servo system being arranged to be individually operative. The adjustment device in an embodiment comprises a continuously running electric motor 1 driving a pump 2 which delivers oil around a closed circuit containing a solenoid valve 3 and an hydraulic motor 4, which motor 4 drives through a worm gear 5 the adjustment shaft 6 carrying a pinion 7 engaging with another pinion on the welding machine. To adjust the transverse wire spacing between zero and maximum the wheel on the welding machine rotates through 60 degrees and the pinion 7 rotates through 360 degrees. To adjust for three wire spacings the shaft carries three cam discs 8a, 8b, 8c which have the same profile and are fixed adjustably to the shaft in the desired angular positions. Each cam co-operates with a follower lever 9a, 9b, 9c, each of which acts through a coupling device 10a, 10b, 10c to a control device which controls the pump 2. The cams are circular around most of the periphery but flatten out over a part in which a notch 8<SP>11</SP> is provided. The follower lever 9 has a sharp nose 9<SP>1</SP> to follow the cam periphery and acts on a coupling member 13, 131, 13<SP>11</SP> connected to a bell crank 14 normally held against a stop 16 by a spring 15. The member 13 comprises an hydraulic cylinder in which slides a'piston and the arrangement is that the piston is normally free to slide in the cylinder so that movement of the cam does not influence the bell crank but when hydraulic fluid is admitted to the cylinder the piston is moved to its fullest extent and the coupling is rigid. The coupling may alternatively comprise a magnetic core slidable in a guide tube and lockable by a solenoid or a spring and rod connection, the bell crank being held against movement under pressure of the spring until a solenoid operated catch is released. By activating the coupling element of a particular cam disc the levers 9 and 14 are connected rigidly, the position of the lever 14 is then determined by the position of the nose 9<SP>1</SP> on the cam and if on the raised part of the cam the pump 2 is controlled to drive the motor 4 which rotates the shaft 6. When the nose 9<SP>1</SP> reaches the flat part the speed of the shaft is reduced and when the notch 8<SP>11</SP> is engaged the motor 4 is stopped, the welding machine having been adjusted. To enable the motor 4 to run in either direction the solenoid valve 3 is provided to change the direction of the supply to the motor 4; the valve being actuated by a signal dependent on whether the previous spacing is greater or smaller than that now required. A programming control, e.g. a punched tape having a track for each cam, is connected so that the coupling members for the cams adjusted to provide different transverse wire spacing are actuated in sequence. Face cams may be used instead of cam discs and programming may be by toothed cam discs.